* {
  margin: 0;
  padding: 0;
}
body{
  display: flex;
  justify-content: center;
}
.calculator input {
  width: 210px;
  height: 30px;
  font-size: 1em;
  text-align: right;
  border: none;
  outline: none;
  color: #333;
  padding: 0 10px;
  box-sizing: border-box;
  border-radius: 5px;
  margin: 10px 0;
}

.buttons button {
  width: 50px;
  height: 50px;
  border-radius: 10%;
}

.numbers {
  float: left;
  width: 160px;
}
.operators {
  width: 50px;
  float: left;
}
.buttons button:hover {
  background-color: #ddd;
}

.buttons button:active {
  background-color: #bbb;
}

.buttons button:focus {
  outline: none;
}

.buttons button:disabled {
  background-color: #eee;
  cursor: not-allowed;
}
